One of the continued problems with therapy in cancer patients is individual differences in response to therapies. With the narrow therapeutic index and the toxic potential of many available cancer therapies, such differential responses potentially contribute to patients undergoing unnecessary ineffective and even potentially harmful therapy regimens. If a designed therapy could be optimized to treat individual patients, such situations could be reduced or even eliminated. Furthermore, targeted designed therapy may provide more focused, successful patient therapy overall. Accordingly, there is a need to identify particular cancer patients which are particularly responsive to particular cancer therapies, either alone or in combination with other chemotherapies. It would therefore be beneficial to provide for the diagnosis, staging, prognosis, and monitoring of cancer patients, including, e.g., hematological cancer patients (e.g., multiple myeloma, leukemias, lymphoma, etc) as well as solid tumor cancer patients (e.g., lung, breast, prostate, ovary, colon, kidney, liver), who would benefit from particular cancer inhibition therapies; or to indicate a predisposition of such patients to non-responsiveness to therapy, thus resulting in appropriate preventative measures.
Proteasome inhibition represents an important strategy in cancer treatment. The proteasome is a multi-enzyme complex present in all cells which play a role in degradation of proteins involved in regulation of the cell cycle. For example, King et al., demonstrated that the ubiquitin-proteasome pathway plays an essential role in regulating cell cycle, neoplastic growth and metastasis. A number of key regulatory proteins, including p53, cyclins, and the cyclin-dependent kinases p21 and p27KIP1, are temporally degraded during the cell cycle by the ubiquitin-proteasome pathway. The ordered degradation of these proteins is required for the cell to progress through the cell cycle and to undergo mitosis. See, e.g., Science 274:1652-1659 (1996). Furthermore, the ubiquitin-proteasome pathway is required for transcriptional regulation. Palombella et al., teach that the activation of the transcription factor NF-kB is regulated by proteasome-mediated degradation of the inhibitor protein IkB. See International Patent Application Publication No. WO 95/25533. In turn, NF-kB plays a central role in the regulation of genes involved in the immune and inflammatory responses. For example, Read et al. demonstrated that the ubiquitin-proteasome pathway is required for expression of cell adhesion molecules, such as E-selectin, ICAM-1, and VCAM-1. See Immunity 2:493-506 (1995). Additional findings further support the role for proteasome inhibition in cancer therapy, as Zetter found that cell adhesion molecules are involved in tumor metastasis and angiogenesis in vivo, by directing the adhesion and extravastation of tumor cells to and from the vasculature to distant tissue sites within the body. See, e.g., Seminars in Cancer Biology 4:219-229 (1993). Moreover, Beg and Baltimore, found that NF-kB is an anti-apoptotic factor, and inhibition of NF-kB activation makes cells more sensitive to environmental stress and cytotoxic agents. See Science 274:782 (1996).
The first proteasome inhibitor described as having antitumor activity, bortezomib (N-pyrazinecarbonyl-L-phenylalanine-L-leucineboronic acid, PS-341) (VELCADE® for injection, Millennium Pharmaceuticals, Inc., Cambridge, Mass.; Johnson & Johnson Pharmaceutical Research and Development L.L.C.) has been approved for treatment of relapsed multiple myeloma. Presently clinical trials are underway in additional indications, including additional hematological cancers as well as solid tumors. This and other peptide boronic ester and acid proteasome inhibitors have been described by Adams et al. See, e.g., U.S. Pat. No. 5,780,454 (1998), U.S. Pat. No. 6,066,730 (2000), and U.S. Pat. No. 6,083,903 (2000). They describe the use of the disclosed boronic ester and boronic acid compounds to reduce the rate of muscle protein degradation, to reduce the activity of NF-kB in a cell, to reduce the rate of degradation of p53 protein in a cell, to inhibit cyclin degradation in a cell, to inhibit the growth of a cancer cell, and to inhibit NF-kB dependent cell adhesion.
Bortezomib specifically and selectively inhibits the proteasome by binding tightly (Ki=0.6 nM) to one of the enzyme's active sites. Bortezomib is selectively cytotoxic, and has a novel pattern of cytotoxicity in National Cancer Institute (NCI) in vitro and in vivo assays. Adams J, et al. Cancer Res 59:2615-22. (1999). In addition, bortezomib has cytotoxic activity in a variety of xenograft tumor models. Teicher B A, et al. Clin Cancer Res. 5:2638-45 (1999). Bortezomib inhibits nuclear factor-κB (NF-κB) activation, attenuates interleukin-6 (IL-6) mediated cell growth, and has a direct apoptotic effect, and possibly an anti-angiogenic effect. Additionally, bortezomib is directly cytotoxic to myeloma cells in culture, independent of their p53 status. See, e.g., Hideshima T, et al. Cancer Res. 61:3071-6 (2001). In addition to a direct cytotoxic effect of bortezomib on myeloma cells, bortezomib inhibits tumor necrosis factor alpha (TNFα stimulated intercellular adhesion molecule-1 (ICAM-1) expression by myeloma cells and ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1) expression on bone marrow stromal cells (BMSCs), resulting in decreased adherence of myeloma cells and, consequently, in decreased cytokine secretion. Hideshima T, et al. Oncogene. 20:4519-27 (2001). By inhibiting interactions of myeloma cells with the surrounding bone marrow, bortezomib can inhibit tumor growth and survival, as well as angiogenesis and tumor cell migration. The antineoplastic effect of bortezomib may involve several distinct mechanisms, including inhibition of cell growth signaling pathways, dysregulation of the cell cycle, induction of apoptosis, and inhibition of cellular adhesion molecule expression. Notably, bortezomib induces apoptosis in cells that over express B-cell lymphoma 2 (Bcl-2), a genetic trait that confers unregulated growth and resistance to conventional chemotherapeutics. McConkey D J, et al. The proteasome as a new drug target in metastatic prostate cancer. 7th Annual Genitourinary Oncology Conference, Houston, Tex. Abstract (1999).
Glucocorticoidal steroids are capable of causing apoptotic death of many varieties of cells, and a selection of glucocorticoidal steroids have consequently be used in the treatment of various malignancies, including lymphoid malignancies, and combination therapies in solid tumors. For example, the optimal therapy for relapsed myeloma is not established, but high-dose dexamethasone is commonly used. See, e.g., Kumar A, et al. Lancet Oncol; 4:293-304 (2003); Alexanian R, et al. Ann Intern Med. 105:8-11 (1986); Friedenberg W R, et al. Am J Hematol. 36:171-75. (1991). Response rates with this treatment are similar to those with vincristine, doxorubicin, and dexamethasone (VAD), and the dexamethasone component is estimated to account for 85 percent of the effect of VAD. See, e.g., Alexanian R, et al. Blood. 80:887-90 (1992); Sonneveld P, et al. Br J Haematol. 115:895-902. (2001). High-dose chemotherapy followed by autologous stem cell transplantation improves patient survival, but in most cases the disease relapses. Attal M et al. N Engl J Med. 335:91-97 (1996); Child J A, et al. N Engl J Med. 348:1875-83 (2003).
In addition to use of dexamethasone, additional corticosteroids have demonstrated use in cancer treatments, including hydrocortisone in combination therapy for prostate cancer, predisolone in leukemia, prednisolone in lymphoma treatment, and triamcinolone has recently demonstrated some anti-cancer activity. See, e.g., Scholz M., et al., J. Urol. 173:1947-52 (2005); Sano J., et al., Res Vet Sci. (May 10, 005); Zinzani P L. et al., Semin Oncol. 32(1 Suppl 1):S4-10. (2005); and Abrams, M T et al., J Cancer Res Clin Oncol. 131:347-54 (2005). It is believed gene transcription resulting from treatment with glucocorticoids results in apoptotic death and therapeutic effect. Analysis of sensitive and resistant cell lines have demonstrated differential gene expression patterns, suggesting expression differences account for varied response rates to glucocorticoid therapy. See, e.g., Thompson, E. B., et al., Lipids. 39:821-5 (2004), and references cited therein.
While advances in development of successful cancer therapies progress, individual patient responses continue to demonstrate subsets of patient response to any particular therapy. We have conducted gene expression analysis studies to assess patient populations undergoing glucocorticoid therapy or proteasome inhibition therapy. Analyses were carried out to identify predictive markers associated with particular patients who respond well to treatment (responders) with a glucocorticoid and/or proteasome inhibitor versus those patients who do not respond to treatment (non-responders) with a glucocorticoid and/or proteasome inhibitor.